Retrievable packers of various types are well known in the applicable prior art. The present invention is concerned with the retrieval of a particular type of retrievable packer, which is a type that is commonly set with the use of an electric wireline setting tool that is pressurized to exert a pulling force on the packer inner mandrel body and a simultaneous pushing force on the packer outer extension sleeve and associated parts, so that the packer slips are moved outwardly and the packing elements are compressed.
This type of packer has conventionally been retrieved with the use of a retrieving tool that is run into the well on a tubing string and is manipulated by the tubing string to achieve packer release and retrieval. Considerable time and effort is required to run a tubing string into and out of a well due to the necessity of coupling each tubing section as the retrieving tool is being run into the well and then uncoupling each tubing section as the retrieving tool is being run out of the well.
It would be advantageous to be able to retrieve the packer with the use of a retrieving tool that is run into and out of the well on an electric wireline and is powered by the same type of electric wireline setting tool that is conventionally used to set the packer. This has not been accomplished in the prior art of which I am aware.
Prior U.S. Pat. No. 3,678,998 Cockrell et al suggests the retrieving of a retrievable packer through use of a wireline running string (col. 1, lines 58-61). However, the retrievable packer is not of the type hereinabove mentioned; an electric wireline setting tool is not used; and manipulation of the wireline (which must be a sandline instead of an electric wireline) is required.
Prior U.S. Pat. No. 3,667,543 Dean suggests the retrieving of a retrievable packer through use of an electric wireline, piano wireline, or sandline (col. 1, lines 38-42). However, the retrievable packer is not of the type hereinabove mentioned; an electric wireline setting tool is not used; and manipulation (upward pull) of the wireline is required.
Prior U.S. Pat. No. 3,542,128 A. L. Owen discloses a retrievable packer that is designed to be retrieved through use of an electric wireline, and prior U.S. Pat. No. 3,503,444 A. L. Owen discloses an electric wireline setting and retrieving tool that is particularly suitable for use with the packer of U.S. Pat. No. 3,542,128 and which setting and retrieving tool is powered by a reversible electric motor. However, the A. L. Owen packer is not of the type hereinabove mentioned and an electric wireline setting tool of the hereinabove mentioned pressurized type is not used.
The objective of the present invention is to provide advantageous apparatus for retrieving retrievable packers of the type hereinabove mentioned through use of a pressurized type electric wireline setting tool hereinabove mentioned. A further objective of the present invention is that the said advantageous apparatus shall include effective provisions to be utilized in the event of malfunction of the electric wireline setting tool.